This disclosure relates to a gas turbine engine, and more particularly to turbine vane platform cooling arrangements that may be incorporated into a gas turbine engine.
Gas turbine engines typically include a compressor section, a combustor section and a turbine section. During operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
Both the compressor and turbine sections may include alternating series of rotating blades and stationary vanes that extend into the core flow path of the gas turbine engine. For example, in the turbine section, turbine blades rotate and extract energy from the hot combustion gases that are communicated along the core flow path of the gas turbine engine. The turbine vanes, which generally do not rotate, guide the airflow and prepare it for the next set of blades.
High pressure turbine vanes are subjected to high operating temperatures and frequently require film cooling on flow path surfaces. Film cooling is facilitated by machining cooling holes to an internal passage or non-flow path pocket surface. A typical solution is to create a cooling air passage under the attachment rail formed by a cantilevered core used in the casting process and fed from the vane pocket.
One example core configuration uses a pair of spaced apart radially extending core portions in the rail that are interconnected by a circumferentially extending core portion within the outer platform. One of the resultant radial passages is welded shut. This type of arrangement is typical for many platforms. Another example core configuration utilizes a single core portion extending through an annular flange of the platform. The core portion branches from the inlet into three dead-ended passages. However, no film cooling holes are connected to these passages, nor is there a circumferentially extending core portion. A core for a typical doublet turbine vane configuration uses two discrete core portions, one for each vane. A single inlet radially extending inlet core portion is joined to a circumferentially extending core portion, which is connected to film cooling holes.